current_users = ['admin', 'Mao Zedong', 'Zhou Enlai', 'Lu Xun', 'Yu Hua']
new_users = ['Mao Zedong', 'Ying Zhen', 'Sun Wukong', 'Lin Zexu', 'He Long']
for index in range(len(new_users)):
    # flag表示名字未被占用，可以使用
    flag = 1
    new_user = new_users[index]
    new_user.lower()
    for index_current in range(len(current_users)):
        current_user = current_users[index_current]
        current_user.lower()
        if new_user == current_user:
            flag = 0
            break
    if flag:
        print('The name ' + new_users[index] + ' is unused.')
    else:
        print('The name ' + new_users[index] +
              ' is used, you need a new name.')
